View Full Version : Water and why is it our leading agent to put out a fire?


Decimator
03-13-02, 01:29 AM
Ok water is made up of hydrogen and oxygen supports combustion and hydrogen is EXTREMELY flammable so why is it that when we combine the 2 we get our largest anti flaimitory agent? Is it just an act of God? A mere Miracle or is there a way to explain it?

my thoughts are that there is a way to explain it but just thinking about it reminds me of how great God is.

Bowser
03-13-02, 04:24 AM
Though I think you have an interesting point regarding water and the duplicity of its nature, you should know that God is pretty much a forbidden taboo around here. When you mention the word "God," you suggest that such a thing exists, and thereby open yourself to a dumpsterload of ridicule and finger shaking.

Is God larger than the heads that crowd this message board? I don't know, but I invite you to argue his case. If you're good at debate, you just might deflate a few egos and bring an end to some bizarre sexual practices.

Adam
03-13-02, 04:33 AM
Oxygen?! Hydrogen?! These are concepts made up by Man!!! The Great God Fumblewumble puts out all fires!!!

Sorry, I was just having fun.

Fire is the material oxidising very fast. A chemical reaction. Part of that reaction requires gaseous oxygen. The oxygen in water is bonded to hydrogen, and does not have the same reaction properties. So, that leaves you with a liquid which will not have that reaction. That liquid nicely covers the burning material (coz liquids do tend to get into all the little nooks and crannies of solids) and prevents the reaction getting its greedy little hands on more gaseous oxygen. It acts as a barrier.

Well, that's my guess. *shrug*


If you're good at debate, you just might deflate a few egos and bring an end to some bizarre sexual practices.


Have you been peeking in my window again?

Bowser
03-13-02, 04:40 AM
I want someone to argue in favor of God's existence. I've tried but don't know enough about it to do a competent job. Just for the challenge, someone give it a try. Boris! You could do it! Yeah...where's Boris?

wet1
03-13-02, 04:45 AM
First off, water isn't always the best material for putting out fires. Depends on the fire and the conditions. It is usually the cheapest and in most cases the easiest to obtain.

You are questioning the properties of water and then asking of it's elements, which have different behaviour. Took a long time to map the phyiscal aspects of the elements and the common compounds that result from their combinations. New ones are still "made" or discovered. Don't believe God had anything to do with it. It's just physical properties. Should you support the "God did it all"; then take it to religion threads and you will find both support and denial there also. If you want aspects of fire then that's ok here.

Flammable metals is one that you don't want to put water on. Magnesium burns hot enough to break the oxygen and hydrogen out and use them for more fuel. You use D class extinglishers for such. Smother it out. Oh, I could give you the triangle of combustion, classes of extinglisher materials, what to do for paints and thinners in containers that are burning, ect. How to fight fires that are flammable gas as opposed to solids and some of them are wicked. Things like commerical applications of using halon for electrical panels but that doesn't answer that water has the property of best putting out the common fire. It is that is one property of water.

Bowser
03-13-02, 04:49 AM
<i>"Don't believe God had anything to do with it. It's just physical properties. Should you support the "God did it all"; then take it to religion threads and you will find both support and denial there also. If you want aspects of fire then that's ok here."</i>

See? I told you so.

You're a little rigid tonight, Wet.

wet1
03-13-02, 04:54 AM
Told you we all had our days...:mad:

I haven't had my morning coffee so I'm not quite human yet...

bbcboy
03-13-02, 06:12 AM
Fire involves a great deal of hot air.

You'll find a lot of that here too but don't let it put you off.
I thought it was a fair question if it's one you don't already have an answer to.
If ya don't ask ya don't learn and there are no such things as stupid questions. Only stupid answers. And those are in plentiful supply.
:D
Peace decimator baby.

Bowser
03-13-02, 01:44 PM
God is watching you, bbcboy...shaking his head, "Tisk, tisk, tisk." <img src = "http://www.sciforums.com/t6203/sc3edc912f5aff7b0ab2edc6902031c7a/images/icons/bugeye.gif">

Chagur
03-13-02, 07:04 PM
Water, when used appropriately, extinguishes a fire by reducing the temp.
of the combustable material to below it's ignition point. Most of the initial
cooling is the result of the water turning to steam.

As wet1 pointed out, there are a number of classes of fire on which the
use of water would be inappropriate.

Take care ;)

GRO$$
03-14-02, 12:51 AM
I remember learning that it smothers the fire, fire suffocates cuz it dosent get oxygen cuz water covers it.... it might be a lil from cooling also tho

Boris2
03-14-02, 05:03 AM
You could look at water as burnt hydrogen and therefore this "ash" puts the fire out.

The shuttle burns hydrogen and oxygen in its main booster and the "smoke" it produces on launch is water vapour.

LeoDV
03-14-02, 08:31 AM
First of all, I'd like to point out that water is not always the best element to put out a fire.

Second of all, the oxygen in water is in H20 form and not 02 - i.e. liquid and not gas, => not flamable.

Third of all, haivng not read that thread, I'll make a lucky guess that either the liquid properties of water separate the burning material from the oxygen it needs to burn, or that water, a great heat medium, uses all the calorific energy of the burning material to turn to vapor, thus putting out the fire.

Either way, it's not a miracle of God. If you believe in Him, then the mere fact that we exist *is* a miracle. No need to look for answers like unexplanable physical phenomenons, or nth party accounts of miracles.

Faith comes from the sky, not the earth, it is God-given, not man-given, and it burns from inside, not from outside.

Decimator
03-15-02, 12:42 AM
wow...ok *fells outranked because of the superior knowledge* but yes i do beleave that god exists and i do beleave that he made everythnig...i was just asking if we have figured out the laws of water.

wet1
03-15-02, 04:33 AM
If you are interested...

Halon is being removed from electrical control rooms as a fire fighting agent. Not that it is not effective but that halon removes available O2 as the way it puts out the fire. That also means if you are trapped in the room when it is used you are a goner. (No breathable O2)

As odd as it sounds, they are being replaced with new microspray technology, using water, that lowers the combustion temp. and somehow smoothers the fire without the danger of water/electrical combination. I am still trying to grasp how that works...

Most effective for broken gas lines, as you would find after an earthquake, is a water spray. A wide fan setting on the nozzle, combined in pairs, this allows a man to get in close to a shut off valve even with a fire around it. You must be cafeful not to let it come from around the corners of the spray as it will envelope you if it can get under, over, or around the spray pattern. Very dangerous, I would not care to do it again...

rain of walrus
03-28-02, 07:54 PM
Fire is so deadly at temperatures where it devours water like a bear eating gummy bears. in many cases ramjets burning rocket fuel can slay a fire where water cannot. And slay it with nothing more than an Oxygen vortex.

Xelios
03-31-02, 08:43 PM
So who made God? =)

Another example of a fire you don't want to put water on is a grease fire. Since grease floats on water, the water will only splash the grease around giving the fire a greater surface area on which to burn. I didn't know about the magnesium though, surely if you put enough water on it would be put out right?

Welcome to Sciforums Decimator =)

Mr. G
04-02-02, 10:25 PM
god(s) seem(s) quite incapable of extinguishing the fire(s) of, um, Hell. }8^p

And, quite evidently, Water actually exists. :D

xvenomousx
04-13-02, 09:38 PM
well my explaination is this:

Water has a very high specific heat capatcity. So water very rapidly sucks heat out of burning material, and of course evaporation of water further disapates more heat.
Also a layer of water splashed over something burning creates a barrier to stop oxygen getting at the fire.
The water and its vapour then provides no free oxygen so combustion cannot continue.

Grease or oil doesn't mix with water, so all water does on a oil fire is splatter it everywhere.
Indycars use methanol as a fuel because of the safety factor - it mixes with water.

Nothing godly or mystical about that.

Stryder
04-13-02, 10:00 PM
Hasn't anyone heard of the Combustion Triangle? (or some other naming) It's basically used to state if something can burn through fire, or how to put it out.

<PRE>
Oxygen
/ \
/ \
/ \
Fuel ----- Heat
</PRE>


Take away any one of them, and fire can not exist. Remove Oxygen and it chokes, remove Fuel and it has nothing left to burn, remove heat and nothing burns.

(something some tutor taught me, for what ever reason)

If you can't understand why water puts out fires, well there is the point that water contains oxygen, but it contains Hydrogen by two parts.

As most have mentioned water cools (removes heat) and can also Smother (remove oxygen as a volatile gas, through entanglement), as well as wet fuel doesn't burn too well.

Of course you should note, don't use water on electrical fires since water might Cool through heat dispersement, but it's also a good conductor.

on radioavtives wave
05-04-02, 06:25 PM
water-- excellent for preventing fires. next time you see a large peice of potassium or sodium and you think to yourself- gee thats a fire hazard- pour some water on it!!!

Gifted
05-15-02, 05:14 AM
First off, don't put water on pottassium or soduim. The metals will take the oxygen from the water in a single replacement reaction, the heat will ignite the resultant hydrogen gas.:rolleyes: In the mean time most of you are correct. water removes two of the corners of the fire triangle: heat and oxygen. The reason it is most common is because class A fires are the most common. If you go to any Air Force base you will find that they will keep at least one hundred-pound bottle of halon near the planes. The electronics, explosives, and expense of the planes automatically removes water from use. About the only thing you can't use halon on are the calss D fires, and you might as well let one of those burn itself out if you can.

They use explosives to put out oil well fires. An explosion in the right place creates a vacuum at the point of cumbustion, suffocating the fire. Happy Birthday!

If ya don't ask ya don't learn and there are no such things as stupid questions. Only stupid answers. And those are in plentiful supply. Amen!
:D

ScotiaB
05-15-02, 08:03 AM
Water is not combustable. It would need nitrogen to be combustable, thats why it doesn't explode.

We use it because it is abundant...

Gifted
05-15-02, 04:32 PM
The water doesn't combust. The reaction goes like this: Li + H2O -> LiO + H2 + heat(somebody balance this, I forgot how aarrgh!:mad: ). The heat is enough to cause the hydrogen to react with ozygen in the air.

ScotiaB
05-15-02, 10:01 PM
I meant adding nitrogen to become an explosive.

and its already balanced =)